The invention relates to a device for placing label sleeves onto containers such as bottles or similar items.
A device is known from U.S. Pat. No. 4,237,675 for the axial placement of label sleeves made of heat shrinkable plastic film material. With the help of an apertured disk which can be moved in a controlled manner longitudinally with respect to a high axis of a bottle, the label sleeve which initially, at the time it enters into the device, is only temporarily positioned from the top onto the bottle shoulder, is shifted axially into the desired final position. If, in this final position, the upper edge of the label sleeve presents only a small radial interval with respect to the shaped shoulder of the bottle exterior, which is pulled inward, it is possible to choose an internal diameter of the apertured disk which is only slightly smaller than the diameter of the label sleeve, so that the apertured disk does not come in contact with the bottle wall. The problem which arises in this context is that, especially in the starting phase of the motion of placement of the label sleeve, its upper edge is very unstable, due to the small material thickness. Thus there is a risk that the label edge will buckle radially inward in the case where a force with axial direction is applied, resulting later during the course of the procedure in its insertion into the opening of the apertured disk, which means that, from that time on, no additional axial movement of the label sleeve occurs.
The invention is based on the problem of providing a device for placing label sleeves onto containers such as bottles or similar items, which device presents an increased operational reliability.
The solution according to the invention provides the advantage that, precisely at the beginning of the placement motion, when, because of the high buckling length of the label sleeve, which in this phase is still largely free standing, the risk of inward buckling is highest, the upper label edge is prevented from sliding through into the free aperture cross section of the label pusher, in an effective manner. During the traction of the placement movement, the free buckling length is continuously decreased as a result of the increasing bracing of the bottle wall on the radial internal side, and, consequently, the risk of a radial inward buckling of the upper label edge continuously decreases.
According to a variant the invention, it is advantageous to hold a bottle, during the axial placement of a label sleeve, in an upright position with its bottom on a standing surface, preferably with axial clamping between its bottom and head area.
According to an additional variant of the invention, it is advantageous, at the beginning of the placement movement, to raise the label sleeve pusher again, after a short downward movement, again in the opposite direction, and then to again carry out a placement movement, which is directed downward, in this case until the final position is reached. By this measure, a preliminary positioning (centering) of the label sleeve which initially is only loosely positioned the bottle with its lower edge, is achieved, which is particularly advantageous in the case of label sleeves that are in a diagonal position.